Aviation manufacturer Boeing on Friday announced plans to cut back production of its 737 aircraft amid global apprehensions about the safety of the 737 Max model in the wake of two fatal crashes in the last six months.

Production will be cut by about 20%, from 52 planes a month to 42 starting mid-April, read a company statement. No end date has been given. The 737 fleet comprises more than just 737 Max aircraft, but that model makes up the majority, according to reports.

“We’re adjusting the 737 production system temporarily to accommodate the pause in MAX deliveries, allowing us to prioritise additional resources to focus on software certification and returning the MAX to flight,” the statement by Chief Executive Officer Dennis Muilenburg said.

In March, 157 people died when Ethiopian Airlines flight JT610 crashed minutes after takeoff. In October last year, 189 people died when Lion Air’s flight ET302 crashed off the coast of Indonesia. Both crashes involved the 737 Max model. After several countries started suspending Boeing 737 Max operations, the aviation manufacturer in mid March announced that it supported the temporary grounding of its entire global fleet of 371 737 MAX aircraft.

“We now know that the recent Lion Air Flight 610 and Ethiopian Airlines Flight 302 accidents were caused by a chain of events, with a common chain link being erroneous activation of the aircraft’s MCAS function,” Muilenburg said. “We have the responsibility to eliminate this risk, and we know how to do it.”

The Maneuvering Characteristics Augmentation System, or MCAS, is an automated safety feature on the 737 Max 8 jets designed to prevent the plane from entering into a stall, or losing lift. Preliminary investigations into both crashes had pointed to a fault in the MCAS that caused the aircraft to nose-dive, probably at an incredibly high speed.

Muilenberg said work was continuing on a software update to enhance the security of MCAS. “Safety is our responsibility, and we own it,’’ he said. “When the MAX returns to the skies, we’ve promised our airline customers and their passengers and crews that it will be as safe as any airplane ever to fly.”

On Thursday, Boeing apologised and accepted responsibility for the crashes but defended the “fundamental safety” system in its planes. The airline is facing multiple lawsuits, including one filed by the family of a passenger on the Ethiopian Airlines flight that crashed.